Income Taxes (Details) - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2026	Mar. 31, 2025
Income Tax Disclosure [Abstract]
Income before income taxes (domestic)		$ 64	$ 38
Federal statutory rate impact		13	8
PTCs (a)	[1]	(31)	(29)
AFUDC equity	[2]	(3)	(1)
Plant related excess deferred taxes	[2]	(1)	(1)
Other	[2]	1	0
State income taxes, net of federal tax effect (c)	[3]	1	1
Income tax benefit		$ (20)	$ (21)
Federal statutory rate		21.00%	21.00%
PTCs (a)	[1]	(49.20%)	(78.00%)
Other		(0.20%)	(0.30%)
AFUDC equity	[2]	(4.10%)	(1.60%)
Plant related excess deferred taxes	[2]	(1.80%)	(3.00%)
Other	[2]	0.90%	0.80%
State income taxes, net of federal tax effect (c)	[3]	1.90%	2.20%
Other		0.20%	3.60%
Effective income tax rate		(31.30%)	(55.30%)
Effective Income Tax Rate Reconciliation, Other Adjustments, Amount		$ 0	$ 1

[1] Wind PTCs (net of transfer discounts) are generally credited to customers (reduction to revenue) and do not materially impact earnings.

[2] Regulatory adjustments primarily relate to the credit of plant related excess deferred taxes to customers for tax rate increases as well as the capitalization of AFUDC equity for book purposes only. Income tax benefits associated with the credit of excess deferred taxes are offset by corresponding revenue reductions.

[3] State and local income taxes are primarily made up of the following jurisdictions: New Mexico, Texas